Our community based participatory research seeks to reduce exposure to asthmagens in the homes of an environmental justice community of Latino children residing in an area of intense dairy and crop based agricultural production. These children with asthma experience high morbidity and our preliminary research finds significant effects of ambient concentrations of fine particulate matter and ammonia. Yet children spend the majority of their time indoors. Studies conducted in urban settings demonstrate that indoor particulate matter (PM) influences asthma outcomes and HEPA (high efficiency particulate air) cleaners can reduce indoor and ambient generated PM. Data on asthma in rural settings is sparse and trials incorporating HEPA portable air cleaners are lacking. This study seeks to characterize key indoor pollutant exposures for [75 children with asthma] who reside within 400 meters of crop production or dairy operations. Subject recruitment utilizes an existing community health worker delivered asthma education program operated by the region's federally qualified health center. Children aged 6-12 years with poorly controlled asthma will be randomized to the usual educational program or an enhanced version, which includes 2 portable room HEPA cleaners (child sleeping area, living room) [with filters designed to reduce PM and ammonia (NH3)]. Children in the usual program group will receive HEPA cleaners at the end of their study year. Prioritizing methods with low participant burden as well as innovative approaches, we will evaluate the effectiveness of the enhanced intervention on 1) Reducing indoor measures of PM and NH3 across seasons, 2. Improving clinically relevant measures of asthma health (Asthma Control Questionnaire, spirometer, oral steroid treatment, unscheduled clinical utilization), and 3. Reducing biomarkers of inflammation (urinary cysteine leukotriene - LTE4, exhaled nitric oxide). Caregiver psychosocial stress and behavioral components will be evaluated as mediators of these effects. The study design, procedures, translation of research results for multiple stakeholders and development of an environmental action plan to control/eliminate exposures are conducted within El Proyecto Bienestar, a longstanding UW-community research to action partnership. The project incorporates each of the NIEHS 2012-17 strategic themes and directly addresses 7 of the 11 sub goals.